Hitherto, an engine automatic stop and restart apparatus has been developed for the purposes of improvement of fuel efficiency of a vehicle such as an automobile and reduction of an environmental load. When predetermined conditions for stopping an engine (for example, an operation of depressing a brake pedal at a vehicle speed equal to or less than a predetermined speed) are satisfied by an operation performed by a driver, the engine automatic stop and restart apparatus automatically performs fuel-cut to automatically stop the engine. Thereafter, when predetermined conditions for restarting the engine (for example, an operation of releasing the brake pedal and an operation of depressing an acceleration pedal) are satisfied by an operation performed by the driver, fuel injection is restarted to automatically restart the engine.
As the engine automatic stop and restart apparatus as described above, there is known an engine automatic stop and restart apparatus for inhibiting, when backward rotation detection estimation means detects or estimates a rotation state of the engine in a backward direction, cranking of the engine by cranking means (starter for the engine) even when a restart condition is satisfied, to thereby prevent an excessive load from being imposed on the starter and a power transmission system (for example, refer to Patent Literature 1).